SIL Verification for Identified SIF Loops & SRS Preparation at IOCL Barauni Refinery

iFluids Engineering
3 min readJan 22, 2025

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Introduction

At iFluids Engineering, we specialize in Safety Instrumented System (SIS) management, providing top-tier SIL verification and SRS preparation services for refineries like IOCL Barauni. Our expertise ensures that all Safety Instrumented Functions (SIF) are correctly identified, verified, and documented, in compliance with the IEC 61508 and IEC 61511 standards, guaranteeing operational safety and risk mitigation.

We provide customized solutions to meet the unique needs of Barauni Refinery with thorough evaluations of safety loops, ensuring optimal functional safety and risk reduction. Trust our team for reliable SIL assessments, efficient SRS documentation, and timely reporting.

The country’s second refinery, the Barauni Refinery, was commissioned in July 1964, with a refining capacity of 1 million metric tonnes per annum (MMTPA) to process Assam (Naharkatiya) crude oil. In 2002, the refinery capacity was revamped to 6.0 MMTPA, with secondary processing facilities such as the Hydrogen Generation Unit (HGU-1), Residue Fluidized Catalytic Cracker Unit (RFCCU), and Sulphur Recovery Unit (SRU) as part of technological advancements.

Indian Oil Corporation Limited has awarded iFluids Engineering to carry out SIL Verification for the identified SIF loops & Preparation of Safety Requirement Specification SRS for Barauni Refinery.

Scope of work

  • SIL Verification is to be carried out for approximately 250 no. of SIF loops identified in the SIL assessment study of Barauni Refinery.
  • Recommendations for implementation are to be suggested if any gaps are identified in the existing system during the SIL assessment study along with the SIL verification report.
  • SIL Verification calculations are to be done using the commercially available, reputed, or proven Software
  • The Safety Requirement Specification (SRS) to be made by EC 61508 I 6151 standards
  • SRS to be prepared for all the SIFs that are indicated in the SIL assessment Report by IOCL

SIL Verification

The Safety Integrity Level (SIL) Study is required to assess the distinct level for specifying the security integrity needs of the security instrumented functions (SIF) to be allotted to the security instrumented systems. Layer of Protection Analysis (LOPA) methodology is followed that accounts for the protective layers to stop to forestall and to mitigate dangerous events with inherently safe design conception, to prevent the incidence / mitigate the results from such unsafe events. Sil verification study is the process of calculating the average probability of failure on demand (or the probability of failure per hour) and architectural constraints for a safety function design to see if it meets the required SIL.

Software Requirements Specification (SRS)

Software Requirements Specification (SRS) is a document that describes what the software will do and how it should perform. The Safety Requirement Specification (SRS), as described by IEC 61511–1:2016, Clause 3.2.72, is the specification that includes the functional requirements for the SIFs and the corresponding safety integrity levels. SRS is a part of the Safety Lifecycle of the Safety Instrumented Systems (SIS), a crucial step in recording each SIF’s safety requirements before the SIS is designed, installed, validated, verified, and operated

Software

The software to be used is exSILentia.

Completion of Project

Project to be completed within 6 months from the date of site Handover

Deliverables

  • Final SIL Verification report to be submitted along with the hardware/software modifications applicable for each SIF.
  • Final report of SRS to be submitted after incorporation of all comments from IOCL.
  • SIL verification workshop to be done at Barauni Refinery
  • Final reports shall be submitted in Two soft copies & one hard copy (3 numbers).

Conclusion

Our expert team at iFluids Engineering ensures comprehensive SIL verification and SRS preparation services for IOCL Barauni Refinery, aligning with international safety standards like IEC 61508 and IEC 61511. We identify and address system gaps to enhance operational safety and minimize risks effectively. Get in touch with us today to ensure your refinery’s safety systems meet the highest standards. Contact fo tailored solutions

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iFluids Engineering
iFluids Engineering

Written by iFluids Engineering

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